Sterilizing package and method and means for sterilizing an article and thereafter checking its sterility

ABSTRACT

MEANS ARE PROVIDED TO INDICATED BY COLOR CHANGE OR LACK OF COLOR CHANGE OCCURRING WITHIN A PREDETERMINE TIME INTERVAL WHETHER A STERILLIZING ENVIRONMENT HAS BEEN ATTAINED IN A SEALED CONTAINER FILLED WITH OZONE MIST. A NEW PACKAGE IS PROVIDED COMPRISING A TRANSPARENT, SEALED CONTAINER HAVING THEREIN AN OZONE MIST STERILIZING ENVIRONMENT, AND ARTICLES TO THE MADE AND KEPT STERILE BY SAID ENVIRONMENT, AND AN INDICATOR ADAPTED TO VISUALLY SIGNAL WHETHER SUCH ENVIRONMENT HAS IN FACT BEEN ATTAINED.

Nov. 28, 1912 c J. VERSES Em 3,704,096

STERILIZING PACKAGE AND METHOD AND MEANS FOR STERILIZING AN ARTICLE ANDTHEBEAFTER CHECKING ITS STERILITY Filed Oct. 16. 1970 INVENTORS F513 IL{far-[$021 ('lzns't Vrses United States Patent M STERILIZING PACKAGE ANDMETHOD AND MEANS FOR STERILIZING AN ARTICLE AND THEREAFTER CHECKING ITSSTERILITY Christ J. Verses, Fairfield, and Eskil L. Karlson, Stamford,Conn., assignor to Pollution Control Industries, Inc., Stamford, Conn.

Filed Oct. 16, 1970, Ser. No. 81,256 Int. Cl. G01d 21/00; G01n 31/22 US.Cl. 23-230 R 4 Claims ABSTRACT OF THE DISCLOSURE Means are provided toindicate by color change or lack of color change occurring within apredetermined time interval whether a sterilizing environment has beenattained in a sealed container filled with ozone mist. A new package isprovided comprising a transparent, sealed container having therein anozone mist sterilizing environment, an article to be made and keptsterile by said environment, and an indicator adapted to visually signalwhether such environment has in fact been attained.

FIELD OF USE This invention relates to sterilizing an article andmaintaining it in sterile condition ready for use at any future time, byplacing it in an ozone mist environment, and to means for indicatingwhether a sterilizing environment has actually been attained; and to asealed package containing ozone mist, the article and the indicatormeans. While applicable to a wide range of articles, use is particularlycontemplated in connection with surgical instruments, surgical glovesand other items of hospital equip- SUMMARY OF THE DISCLOSURE An articleto be made sterile is placed in a transparent container such as aplastic bag which, after being evacuated, is refilled with a mixture ofozone gas and water particles under pressure. When this mixtureencounters the low pressure within the newly evaucated container thewater particles explode forming an intimate mixture of ozone gas andfinely divided water particles, referred to herein as ozone mist. Theamount of ozone in the mixture of ozone gas and water particles forcedinto the bag under pressure is suflicient to provide in the container anozone concentration of one thousand (1,000) parts per million(1,000,000) by weight. The amount of water in the mixture which isforced into the bag is sufiicient to establish a condition ofsaturation, or at least 80% humidity, within the bag after it is sealed.The container is then vibrated or tumbled to expose the entire surfaceof the article to the ozone mist. As a check, in order to be 3,704,096Patented Nov. 28, 1972 sure that in the sealed bag there is sufiicientozone concentration and suflicient humidity to kill all germs andviruses which may be on the article or on the inner surface of the bag,means are provided and included in the bag which are adapted to indicateby a color change occurring within a predetermined period of time aftersealing of the bag that a sterile condition has been attained within thebag, or to warn by lack of color change that a sterile condition has notbeen attained.

The invention will be best understood by reading the followingdescription in connection with the drawing, in which the figure is anelevation of a sealed flexible plastic bag having therein an article tobe sterilized in an environment of ozone mist, and containing also colorspeci mens adapted to indicate by complete color change or lack of suchchange whether a dependable sterilizing condition has been attainedwithin the sealed bag.

DESCRIPTION In practicing the invention in accordance with theembodiment thereof disclosed herein an article 10 to be sterilized isplaced in a container, preferably in a transparent container such as aplastic bag 12 and along with two color specimens 22 and 26 the functionof which is described below, the bag is first evacuated and then filledwith ozone mist, the presence of which is indicated by numeral 18, andsealed. A mixture of ozone gas and water is preferably supplied intothis bag under pressure and expands to form a fine mist. The article inthe container is made to move and expose all of its surfaces to theozone mist. The exhausting of the bag 12, refilling it with ozone mistand vibrating the article within the bag may desirably be done by themethod and apparatus disclosed in copending US. patent application Ser.No. 81,255 filed Oct. 16, 1970.

The concentration of ozone necessary to kill all germs and viruses on anarticle enclosed in the bag 12 may vary with the locality and altitudebut tests indicate that a concentration on the order of one thousand(1,000) parts by weight of ozone per million (1,000,000), in anenvironment sufficiently humid to promote the effectiveness of the ozoneand to bring the ozone into contact with the entire surface of thearticle, will produce a reliable overkill situation. The humidity shouldbe or more at room temperature.

If the amounts of ozone and water supplied into the bag 12 arecontrolled to give the ozone concentration and humidity percentagereferred to above, optimum results will be attained, but as a check todetermine, after the bag 12 is sealed, whether the article therein hasbeen made completely sterile, the color change indicator means referredto above are employed.

In the drawing a pair of surgical shears is shown as the article 10 tobe rendered sterile and maintained in sterile condition. A strip ofadhesive tape 20 having on it a spot 22 of Safranin O dye is shownapplied on one handle of the shears and a strip of adhesive tape 24having on it a spot 26 of cobaltous chloride is shown applied ontheother handle of the shears. The spots 22 and 26 can be seen throughthe wall of bag 12 and any change in color of these spots can beobserved.

Safranin O is a dye, also known as aniline rose or aniline pink,prepared by oxidizing para-toluylenediamine aniline and ortho-toluidine.It is made by National Aniline Division of Allied Chemical Corporation.When exposed to ozone, Safranin O bleaches and loses its characteristicTABLE Concentration of Safranin (by weight): 25

Time for complete bleach (minutes) Dehydrated cobaltous chloride, CoCl6H O, which is blue, turns red almost immediately when placed in anenvironment where the humidity is 80% or more. Since this humidityindicator reacts much faster than the said ozone concentration indicatorboth color indicators may be observed at the end of the time intervalrequired to eifect a complete color change of the Safranin indicator.

By observing both indicators 22 and 26 promptly after the periods oftime indicated in the table, one can visually determine whether in facta condition has been obtained in the bag to render the article 10therein completely sterile.

What we claim is:

1. The method of indicating whether ozone mist, comprising mixture ofozone gas and finely divided water particles, sealed in a transparentcontainer along with an article to be sterilized has high enough ozoneconcentration and humidity to sterilize the said article, whichcomprises, enclosing in the container, along with the article and ozonemist, a specimen of Safranin O and a specimen of dehydrated cobaltouschloride and observing the said specimens for color change after a timeinterval within which said Sa-franin O and said dehydrated cobaltonschloride are known to change color in a concentration of ozone and underconditions of humidity known to kill germs and viruses.

2. A package comprising a sealed transparent container having therein,ozone mist, an article to be rendered sterile by the ozone mist, andspecimens of Safranin O and dehydrated cobaltous chloride to indicate bychange of color, occurring within a predetermined time intervalfollowing sealing of the container, whether the desired sterilecondition within the container has been attained.

3. The package claimed in claim 2 in which the indicator responsive to agerm-killing concentration of ozone is Safranin O and in which theindicator responsive to the humidity of the environment is dehydratedcobaltous chloride.

4. The package claimed in claim 2 in which the specimens of Safranin Oand dehydrated cobaltous chloride comprises thin strips of adhesive tapeapplied to the article and stained respectively with Safranin O' anddehydrated eohaltous chloride.

References Cited UNITED STATES PATENTS 1/1949 Davis 23253 TP 11/1969Andersen et al 2191 OTHER REFERENCES Kolling et a1., Chem. Abstr. 55,2559lh (1961).

MORRIS O. WOLK, Primary Examiner R. M. R-EESE, Assistant Examiner

